Thanks to what’s being called a mechanical battery, Ontario’s electricity system can store excess energy for the first time.

Housed in a steel clad building in Harriston, about 120 km north of London, the storage system was hooked up to Ontario’s electricity grid Tuesday.

“Up until now it has been impossible for us to store electricity,” said Ontario Energy Minister Bob Chiarelli, who was in Harriston for the historic event.

“It is extremely exciting. When it gets some traction in the system it is going to make a much more efficient system. It is going to save money​,” he said.

Chiarelli said the facility is a small start with big potential.

“It is very clear to most observers now that this could be expanded significantly across the province over time,” he said.

The storage system built in Harriston is for two megawatts, a relatively small amount, said Annette Verschuren, chair and chief executive officer of NRStor, the Toronto-based company that owns the facility.

But Verschuren said she expects much larger electricity storage facilities will be built in the future using the Ontario-made technology.

“We see hundreds of megawatts on the Ontario system alone, and that’s not talking about the opportunities throughout Canada. We see this technology being exported,” Vershuren said.

A representative of New Brunswick Power was in Harriston to get a first-hand look at the facility.

Chiarelli said the flywheel storage system won’t replace generating plants but it will make the existing facilities more efficient.

“They will waste less electricity and the system operator will have a much more efficient tool to get energy in and out of the system, he said.

Ontario has already requested proposals from companies for an additional 50 megawatts of storage.​

Storing electricity has been a dream of provincial electricity system operators who have to constantly gear up and down generating plants in order to match consumption.

Too much or too little electricity in the grid can trigger blackout or brownouts.

Developed by Temporal Power, a privately owned Ontario company, the mechanical battery storage system opened in Harriston consists of 10 flywheels encased in reinforced concrete vaults, and placed six metres below ground.

The flywheels are three metres high and a metre across and spin at up to 11,000 rpms.

When there’s excess electricity in the system, the flywheels are powered by a motor and take energy out of the system.

When energy is needed back into the system, the flywheels can instantly feed the electricity back.

BONUS BENEFIT

The storage system could help solve one of the problems with wind energy — power being generated when it isn’t needed and not available when it is.

“With this facility you could take the excess wind that blows at night and really increase performance,” said Annette Verschuren of NRStor, the Toronto-based company that owns the facility.